The present invention relates to a method and an apparatus for tying one or more articles such as reinforcing bars for construction or structural purposes, flexible containers such as bags, or the like.
As a method of tying one or more articles, particularly an overlapped portion of articles such as reinforcing bars for construction or structural purposes, or the like, there is known a method in which a worker for arranging, or placing in position, reinforcing bars winds a single piece of annealed steel wire of a predetermined length around the overlapped portion of the reinforcing bars in situ or on a construction site. It is also known to use as a tying wire a U-shaped fold or loop of an annealed steel wire which is already cut into a predetermined length. In such a case, a hooked end of a twisting tool is engaged with a closed end of the U-shaped fold. The twisting tool is then manually twisted or turned several times to thereby twist together the front end and the rear end of the U-shaped fold.
In the above-described conventional method of manually twisting a single piece of steel wire around one or more articles, particularly around the overlapped portion for tying, it is necessary to strongly hold both ends of the steel wire before winding it around one or more articles, particularly around the overlapped portion. This manual work is troublesome and a mechanical means for holding both ends was difficult to devise. If this strongly held portion gets loosened, it becomes impossible to twist the steel wire as well as to firmly and immovably tie the overlapped portion together. If the twisting is carried out excessively to ensure the tying of the articles, the steel wire may give rise to rupture. Further, in the above-described conventional method it is normal practice to hold both ends of the tying wire to be twisted with one hand and insert the hooked end of the twisting tool into the front end of the loop with the other hand, thereafter rotating the twisting tool on the construction site. This job requires a high degree of skill, and it has to be repeated many times, especially in view of tying, for example, all of the overlapped portions of the reinforcing bars on one construction site. This repetition is a hard work for the worker, and the time to be spent for this particular job becomes long. As a result, the efficiency of the tying work is lowered.